Proton and carbon-ion minibeam therapy: from modeling to treatment

Arrays of minibeams of protons and $^{12}$C in tissue-like media were modeled with Geant4 toolkit. A set of beam energies was used in simulations to provide a Spead-out Bragg peak (SOBP) extended by 6 cm in depth for protons as well as for $^{12}$C. In both cases, beams of 0.3 mm or 0.5 mm FWHM were arranged at the entrance to a water phantom either on a rectangular or an hexagonal grid to compare two kinds of projectiles and different minibeam patterns. Differential and cumulative dose-volume histograms (DVH) were calculated and compared for protons and $^{12}$C as dose uniformity metrics. A uniform dose distribution was easily achieved with protons due to an enhanced lateral scattering of these projectiles in comparison to $^{12}$C. The cumulative DVHs calculated for 0.3 mm or 0.5 mm minibeams almost coincide in the target volume, but diverge for different grid patterns. In contrast, cumulative entry DVHs were found similar for both grid patterns, but different for 0.3 mm and 0.5 mm minibeams.Comment: 8 pages, 5 figures, talk given at the XXV International Baldin Seminar on High Energy Physics Problems "Relativistic Nuclear Physics and Quantum Chromodynamics", September 18-23, 2023, Dubna, Russi

A discrete slug population model determined by egg production

Slugs are significant pests in agriculture (as well as a nuisance to gardeners), and it is therefore important to understand their population dynamics for the construction of efficient and effective control measures. Differential equation models of slug populations require the inclusion of large (variable) temporal delays, and strong seasonal forcing results in a non-autonomous system. This renders such models open to only a limited amount of rigorous analysis. In this paper, we derive a novel batch model based purely upon the quantity of eggs produced at different times of the year. This model is open to considerable reduction; from the resulting two variable discrete-time system it is possible to reconstruct the dynamics of the full population across the year and give conditions for extinction or global stability and persistence. Furthermore, the steady state temporal population distribution displays qualitatively different behavior with only small changes in the survival probability of slugs. The model demonstrates how small variations in the favorability of different years may result in widely different slug population fluctuations between consecutive years, and is in good agreement with field data

Analysis of the low temperature ceramics structure with consideration for polydispersity of initial refractory components

The results of computer simulation of the structure and physical properties of sintered low-temperature ceramics specimens with different volume fractions of different components of refractory components are presented. Properties of sintered ceramics, residual porosity, and shrinkage anisotropy are determined by features of packing of various fractions of refractory particles. The results indicate the determining factor of the presence of particles of the coarse fraction of refractory components capable of forming a internal skeleton of interacting particles

Mutations in human genes that increase the risk for severe influenza infection

The system of genetic control of innate immune responses to influenza infection and gene function allows for the development of systemic treatment of influenza with a focus on the phenotype of mutations based on individual genetic susceptibility to severe disease and/or the development of complications.The system of genetic control of innate immune responses to influenza infection and gene function allows for the development of systemic treatment of influenza with a focus on the phenotype of mutations based on individual genetic susceptibility to severe disease and/or the development of complications

Measurements of integral muon intensity at large zenith angles

High-statistics data on near-horizontal muons collected with Russian-Italian coordinate detector DECOR are analyzed. Precise measurements of muon angular distributions in zenith angle interval from 60 to 90 degrees have been performed. In total, more than 20 million muons are selected. Dependences of the absolute integral muon intensity on zenith angle for several threshold energies ranging from 1.7 GeV to 7.2 GeV are derived. Results for this region of zenith angles and threshold energies have been obtained for the first time. The dependence of integral intensity on zenith angle and threshold energy is well fitted by a simple analytical formula.Comment: 4 pages, 4 figures, 1 tabl

Economic tools for realization of methane production project on Kuzbass coal deposits

Environmental issues and, above all, issues related to the release of greenhouse gases into the atmosphere, such as coal bed methane, actualize the challenge of searching a variety of options for its disposal. The difference in the macroeconomic, industrial, geological and infrastructural features determine the need to choose the most cost-effective option for using of methane emitted from the coal deposits. Various economic ways to improve the profitability of production are viewed on the basis of the analysis of methane production project from Kuzbass coal deposits, Kemerovo region, Russia

Changes in the spectrum of protein components and the concentration of phospholipids of the erythrocyte membrane in patients with ulcerative colitis

Ulcerative colitis is a chronic inflammatory bowel disease with unclear etiology. An insufficient amount of data on the etiopathogenetic mechanisms of the disease creates opportunities to research them at the cellular level, including the membrane level. Since the functional state of the cytoplasmic membrane largely depends on protein-lipid interactions, we studied the effect of the proportional ratio of three proteins (glucose transporter, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and glutathione-S-transferase (GST)) on the level of phosphatidylethanolamine and phosphatidylcholine in the erythrocyte membrane of patients with ulcerative colitis during an acute attack. The study involved 51 patients with ulcerative colitis during the acute attack and 26 clinically healthy individuals. The groups are comparable by gender and age to study the proteins of the cytoplasmic membrane, Laemmli electrophoresis technique in polyacrylamide gel was used, followed by an assessment of the intensity of protein bands staining on electropherograms. Phospholipid fractions were obtained using thin-layer chromatography and their content was assessed using the Mathcad 2001 Professional system. Statistical processing was carried out by the program Statistica 10.0 for Windows. Changes of phosphatidylcholine and phosphatidylethanolcholine levels in patients and healthy individuals are not of the same type and are interrelated with changes in the proportion of membrane proteins of the glucose transporter, GAPDH and GST. The proportions of proteins that affect the level of phospholipids have calculated. In patients with ulcerative colitis, a decrease in the level of the studied membrane lipids have revealed in comparison with the clinically healthy group, in addition, an increase in the proportion of the glucose transporter and a decrease in the proportion of GST have noted. In addition, the relationship between an increase in the level of the cytoplasmic membrane phospholipids in ulcerative colitis and a change in the proportion of GAFDH in a smaller direction, which slows down the process of glucose oxidation, was determined. The obtained data confirm the strengthening of the processes of antioxidant protection and the increased need for energy supply of the cell membrane in patients with ulcerative colitis during an acute attack

RED-CELL MEMBRANE PROTEINS AND DIAMETER-THICKNESS RATIO IN PATIENTS WITH ESSENTIAL ARTERIAL HYPERTENSION COMPLICATED AND NON-COMPLICATED WITH METABOLIC SYNDROME

Change in structural and functional properties of red cell membrane proteins in patients with the essential arterial hypertension (EAH) can promote development of significant dysfunction of these cells and can complicate the course of a system hypoxia in this category of patients. The aim of our research was to determine the interrelation between red cell sphericity and the level of proteins of their membrane in patients with EAH complicated and non-complicated with metabolic syndrome (MS). 51 male patients with EAH I and II (average age - 42 ± 1.5 years) were examined and divided into 2 groups: group 1 - 29 patients with EAH complicated with MS; group 2 - 22 patients with EAH non-complicated with MS. Protein spectrum was assessed by 10 red cell membrane proteins. Results. Patients with EAH complicated with MS had decrease in spectrin level and loss of correlations between the levels of red cell membrane proteins. Number of patients with diameter-thickness ratio < 3.4 (indicates the existence of cells prone to spherocytosis) in the group 1 was twice more than in the group 2 (29.4 % vs 13.7 %). Conclusion. We determined structural and functional disorders in interrelations of such membrane proteins as a-spektrin, ATP and GAPDH (in patients with EAH complicated with MS), and ATP, GAPDH and actin (in patients with EAH non-complicated with MS) which promote development of acquired spherocytosis and further impairments in microcirculation and gaseous metabolism in tissues

Effects of Interaction of Protein Components of erythrocyte Membrane in Healthy Individuals and Patients with Ulcerative Colitis

Background. It is known that in ulcerative colitis there is a violation of the barrier function of the colon mucosa, which can lead to pathological changes inside cells, including in the membranes of red blood cells. The stability of the erythrocyte membrane and its ability to deform largely depends on the composition and interaction of protein structures inside it. A significant decrease in the content of the main protein components of the erythrocyte membrane in ulcerative colitis was found in comparison with healthy people.Aim of the research. Taking into account the available data, we conducted an additional study to analyze the effects of the relationship between the protein components of the cytoplasmic membrane of erythrocytes in patients with ulcerative colitis and clinically healthy people.Materials and methods. The study involved men and women with ulcerative colitis in the period of exacerbation (n = 51) and clinically healthy individuals matched by sex and age (n = 30). The analysis of the interaction effects of ten main protein components of the erythrocyte membrane was carried out. For each protein under study, its average value was determined, and within the studied groups all proteins were divided into two categories – above and below their average level. Analysis of variance was used to quantify the contribution of each identified factor.Results. It was found that the effect of the relationship is not inherent in all categories of protein components. In ulcerative colitis, the effects of interaction with such important structural proteins as spectrins and ankyrin disappear. In the effect of band 4.1 protein, in contrast to clinically healthy individuals, a new independent factor appears – glyceraldehyde-3-phosphate dehydrogenase, and in the effect on actin – an anion-transport protein.Conclusion. In ulcerative colitis, significant changes occur in the membrane of red blood cells, leading to a violation of the relationships between proteins, a decrease in the total content of the studied proteins and the loss of some of the effects of independent factors on the level of certain protein structures. Based on the findings, adjustments can be made to the treatment of ulcerative colitis in order to strengthen the erythrocyte membrane